The two sides began bargaining in February. About 1,200 employees at the mine are members of the USW and three other unions: the International Union of Operating Engineers, the International Association of Machinists and the International Brotherhood of Electrical Workers.

“We’re pleased with the productive relationship that we have built with Rio Tinto and with the other unions at Kennecott,” said USW International president Leo W. Gerard.

Rio Tinto-Kennecott is a mining, smelting and refining facility that includes one of the largest open-pit copper mines in the world, located in the south end of the Salt Lake Valley.

“This agreement ensures that the facility will continue to provide good-paying, family-supporting jobs and that the company can continue to operate safely and efficiently,” said USW District 12 director Robert LaVenture.